I am interested in integrating BIAB with Logic Pro using the DAW plugin.

But...
I am concerned about integrating the BIAB plugin into a Logic project with adjustable tempo, key, and meter.

If I understand correctly, the BIAB DAW plugin maintains its own independent tempo, key, and meter settings, and does not "listen" to the DAW for changes to those settings.

Is this true? Shouldn't a "plugin" listen to the basic performance settings of the DAW that is controlling it?

If the BIAB plugin doesn't respond to Logic's tempo and meter changes then please consider this a feature request. If it's an unrealistic request (does the AU plugin API not communicate tempo changes?) then that stinks.

If the BIAB plugin is responsive to Logic's tempo and meter changes, then please confirm that it will... this is a crucial feature.

The plugin API in general does respond to tempo and meter changes, but the DAW does not communicate those changes except when it's playing and only at the time the change happens. Band-in-a-Box has to generate the Realtracks before it can play them, so it has to know the tempo and meter information before the song is played.

I'm not certain if the plugin API can communicate key changes, but the above would still apply - BB has to generate the Realtracks ahead of time, so it would have to know the key changes when it's generating and can't respond to them in real time.

This makes sense. How about when NOT using RealTracks, but just MIDI generated ones?

Same thing - BB has to generate the MIDI data ahead of time.